Mixed quantum–classical simulation of vibrational frequency modulations of a diatomic molecule in a rare gas fluid

A simple adaptation of the Lanczos algorithm is presented for use in vibrationally adiabatic mixed quantum–classical molecular dynamics simulations. As an illustration, results are given for the test case of a vibrating diatomic molecule in a rare gas fluid. The approach is found to be both efficient and accurate. Prospects for further improvements and applications are discussed.